The HM Revenue and Customs website held up last week as the final flurry of self-assessment tax returns were submitted in the days leading up to the 31 January deadline.
At the peak of filing on Monday and Tuesday last week (30, 31 January 2006), the site was processing about 8,700 returns an hour, taking the total number of submissions in January to 719,000.
In all, nearly two million self-employed taxpayers filed their returns online - up 38% in a year.
Despite the increase, no problems were reported with the system. HMRC chairman David Varney said, "This was due to HMRC managing the filing peak closely, enhancing our IT infrastructure and improving our system monitoring."
Last year the Inland Revenue was forced to give a 14-day extension to taxpayers who submitted their returns online before the deadline but did not receive an electronic validation confirming receipt.
In the run-up to last week's deadline, the HMRC website was urging taxpayers to avoid filing returns during peak periods, but in the event the system was able to keep up with demand.